Ok is there a standard for good definition or is it something that is up to personal taste? There are stories of some lens manufacturers reducing the published coverage figures over the years. The only change supposedly being how they defined good definition.

I guess what I'm asking is. Just how much can I get away with when looking at older lens? One of the sellers on Ebay uses coverage figures that far exceed anything I can find published. He seems very well respected so I'm guessing he isn't puffing things up unfairly.

I'm guessing this is one of those questions that can't really be answered since it's too dependent on each different lens.